1. Technical Field
This invention relates to containers such as blow molded plastic jugs which are widely used in the dairy industry and others for the expendible packaging of dairy products and other liquids and tamper indicating caps for engagement thereon.
2. Description of the Prior Art
Prior neck finishes on containers of this type may be seen in U.S. Pat. Nos. 2,162,711 of June, 1939, 2,162,712 of June, 1939, 3,650,428 of Mar. 21, 1972, 3,980,195 of Sep. 14, 1976, 4,354,609 of Oct. 19, 1982, 4,402,415 of Sep. 6, 1983, 4,418,828 of Dec. 6, 1984, 4,497,765 of Feb. 5, 1985, 4,534,480 of Aug. 13, 1985 and 4,561,553 of Dec. 31, 1985.
In each of the above U.S. patents there are individual neck spiral thread configurations which require a cap with a matching single spiral thread configuration for engagement thereon and have the common fault of requiring selective testing rotation of the cap on the threaded neck of the container before the single thread patterns engage.
Additionally, partial semi-annular thread patterns comprising ribs are disclosed in U.S. Pat. Nos. 4,589,561 of May, 1986 and 4,666,053 of May 19, 1987.
In the '561 patent several short angular ribs are circumferentially spaced on the inner surface of the depending annular wall of a cap and in the '053 patent a pair of vertically spaced short annularly disposed ribs are disclosed on the neck finish of a container.
The present invention provides an improved novel neck finish for a container such as a blow molded plastic jug on which a multiple spiral thread pattern configuration of continuous spiral threads are arranged in vertical and circumferentially spaced relation to one another together with a thin wall plastic cap that may be pushed onto the container, the cap having a top and a depending annular wall with a multiple annular spiral thread patterns circumferentially and vertically spaced formed on the inner surface of said depending wall of the improved cap. The combination of the improved cap and improved neck finish of the container result in a rapid and positive engagement of the multiple continuous spiral thread patterns on the respective neck finish with those on the inner surface of the depending wall of the cap.